Process for dyeing or printing shaped
structures of linear aromatic poly-
esters, especially polyethylene ter-
ephthalates



United States Patent of Germany No Drawing. Filed Dec. 17, 1962, Ser. No. 244,933

Claims priority, application Germany, Dec. 27, 1961, 4 Claims. (c1. 3-41 The dyeing is carried out in the presence of a carrier 7 at a temperature within the range of about 95 to 105 C. and preferably about 100 C. or, by the high temperature process, in the absence ofa carrier at a temperature within the range of about 12 to 140 C. and

preferably between about 125 and 130 C. Printing is advantageously carried out by applying the dispersed dyestuff to the shaped structures by printing and subjecting the printed shaped structure to a short dry heat treatment at a high temperature, for example, of about 200 C.

As carriers which are suitable for the process of the present invention there may be used, for example, o or p-phenyl phenol, salicylic acid esters, methyl salicylic acid esters, mono-, diand trichlorobenzenes, benzoic acid and methyl naphthalene. In order to improve the fastness to abrasion, the dyeings or prints produced according to the process of the present invention may be after-treated in an alkaline reducing bath which may contain, for example, sodium dithionite, sodium hydroxide and a detergent.

The dyestufi shows a good affinity to structures of aromatic polyesters and a good ability of building up, even when dyeing at 100 C. in the presence of carriers. The dyeings obtained are distinguished by their excellent fastness to light and their very god fastness to thermo-fixation.

The following examples serve to illustrate the invention but they are not intended to limit it thereto, the parts being by weight unless otherwise stated and the relationship of parts by weight to parts by volume being the same as that of the kilogram'to the liter.

Example 1 100 grams of yarn of polyethylene terephthalate are treated for 90 minutes at a goods-to-liquor ratio of 3,185,787 Patented June 1, 1965 ice 1:30 in a bath of 100 C. containing 0.8 gram of the disazo-dyestufi of phenol-(4 azo 1)-benzene-(4 azo 4)- phenol in a finely divided form and 4 grams per liter of a carrier based on o-phenyl phenol. The goods are soaped and then subjected to an after-treatment for 15 minutes at to C. in a reducing bath containing per liter 2 grams of sodium dithionite 2 ml. of sodium hydroxide solution of 38 B6. and 0.5 to 1 gram of a non-ionic synthetic detergenttpolyglycol ether) in order to improve their fastness to rubbing. There is obtained a reddish yellow dyeing possessing a very good fastness to light and to thermofixation.

Example 2 25 grams of a fabric of polyethylene terephthalate are printed with a printing paste containing per kilogram 50 grams of the disazo-dyestufi of phenol-(4 azo 1)-benzene- (4 azo 4)-phenol, 200 grams of narka rubber, 50 grams of napththoldiglycol ether and 700 grams of water. The goods are then dried, fixed for 30 seconds at 200 C. and finally subjected to an after-treatment in a reducing bath as described in Example 1. There is obtained a yellow print possessing good fastness properties.

We claim:

1. A process for dyeing and printing fibrous materials of polyethylene terephthalates, which comprises applying to said materials at about to 140 C. from an aqueous dispersion the disazo dyestufi phenol-(4 azo 1)-benzene- (4 azo 4)-phenol of the formula 2. The process as claimed in claim 1, wherein the dyeing is carried out in the presence of a carrier at a temperature between about 95 and C.

3. The process as claimed in claim 1, wherein the dyeing is carried out in the absence of a carrier at a temperature between about and C.

4. The process as claimed in claim 1, wherein the printed fibrous materials are exposed to a short dry heat treatment at about 200 C.

References Cited by the Examiner UNITED STATES PATENTS 2,663,612 12/53 Gibson.

2,881,045 4/59" Mecco et a1.

2,926,987 3/60 Freyermuth et a1.

2,934,397 4/60 Landerl.

3,096,140 7/63 Gaetani' 8/41 NORMAN G. TORCHIN, Primary Examiner. 

1. A PROCESS FOR DYEING AND PRINTING FIBROUS MATERIALS OF POLYETHYLENE TEREPHTHALATES, WHICH COMPRISES APPLYING TO SAID MATERIALS AT ABOUT 95 TO 140*C. FROM AN AQUEOUS DISPERSION THE DISAZO DYESTUFF PHENOL-(4 AZO 1)-BENZENE(4 AZO 4)-PHENOL OF THE FORMULA 